Bill BLAKE
(Bill Blake Heritage Documentation/kubit GmbH, Germany)

Abstract: Speed, cost and drawing production methods are examined by looking at 2 recent projects where rectified photography was used as a rapid method of metric capture for CAD drawing production for conservation projects.
The projects are the preparation of conservation plans of the roof pavement at Martello Tower 24, Dymchurch Kent, UK and the plan of Stable floor at Attingham Park Staffordshire, UK.
By using a simple pole (PAP) technique with a gyro stabilised remote controlled camera optimum photo-cover was achieved. By digitising key features with TST with a real-time CAD interface at the same time as photo-capture confidence in the point density for control with the minimum density was possible.
Image rectification in AutoCAD by use of PhoToPlan allowed a variety of image orientations to be used successfully and production of ortho-image in the first project and digitised line work in the second. Using the camera by remote control is an advantage because this allows the pole to be tilted so that nadir photo cover avoids shots of the pole

Keywords: CAD drawing production, Conservation plan data, Heritage documentation, Low cost surveying, PAP (Pole Aerial Photography)